Sewing mechanism



Jan.20, 1942. A, ITCHELL A 2,270,761

SEWING MECHANISM Original Filed July 2, 1957 a 8 Sheets-Sheet 1 "v o o [Ill m a; g l m 1 L w s: mg; g n! mg I rr-| N m m I 2. LL.

INVENTORS ALLISTER $.MITO HELL ATTORNEYS Jan. 20, 1942. A. s. MITCHELL ETAL SEWING MECHANISM Original Filed July 2, 1937 8 Sheets-Sheet 2 INVENTORS ALLISTER $.MITCHELL HAROLD ".RATLEY BY CLARENCE J. DAVIES WWW +fl% ATTO Jam- 20, 1942.

A. S. MITCHELL ETAL SEWING MECHANISM Original Filed July 2, 1937 s Sh eets-Shee t s INVENTORS ALLISTER sxrrcueu. BY HAROLD mmmzv CLARENCE J.DAVIE$ TTORNEYS Jam 1942- I A. S..MITC.HELL ETAL 2,270,761

SEWING MECHANISM Original Filed July 2, 1937 8 Sheets-Sheet 4 FIGS. my 39 49 49* Q 39 Halo;-

INVENTOR$ ALLI STIR 8. MITCHELL HAROLD I. RATLEY CLARENCE J. DAVI E8 Jan- 20, 1942- A. s. MITCHELL EI'AL SEWING MECHANISM ori ih al Filed July 2, 19:57 a Sheets-Sheet 5 INVENTORs ALLISTER smiTcHEu'. HAROLD M. RAT

LEY

. AVIES cuasucz a u w m'romvays Jan. 1942- A. s. MITCHELL ETAL 2,270,761

SEWING MECHANISM Original Filed July 2, 1937 8 Sheets-Sheet 6 39g I I 42,

I NVEN TORS 'ALLISTER smrcusu.

HAROLD .RATLEY C ARENCE J.DAV|E$ WWW'WTTORNEYS 1942- A. s. MITCHELL ETAL 2,270,761

SEWING MECHANISM Original Filed July 2, 1937 8 Sheets-Sheet 7 INVENTORS ALLISTER 8. NITQHELL HAROLD M. RATLEY CLAR uczwmsa- ATTORNEYS Jan. 20, 1942- A. s. MITCHELL ETAL 2,270,761

SEWING MECHANISM Original Filed July 2, 1957 8 Sheets-Sheet s INVENTORS ALLISTER $.IITGHELL BY HAROLD ".RATLEY CLARENCE J. DAVIES Patented Jan. 20, 1942 UNITED STATES PATENT OFFICE SEWING MECHANISM National Automotive Fibres, Ina,

Detroit,

Mich., a corporation of Delaware Original application July 2, 1937, Serial No. 151,726. Divided and this application August 17, 1939, Serial No. 290,686

V 29 Claims.

This invention relates particularly to a sewing machine for making pleated upholstery, such as used on automobile cushions, door panels and the like. This application is a division of our copending application, Serial No. 151,726, entitled Sewing machine with automatic threading head, filed July 2, 1937. l I

The primary object of the invention is to provide an improved sewing-mechanism which is capable of rapid operation and able to sew through heavy cardboard panels, if desired. A further object of the invention is to provide a sewing-mechanism characterized by thelocation of a pair of co-acting needles at the same side of a fabric and carried by the same support.

The improved sewing-mechanism is adapted .for use on a standard multipleater machine of the type shown in Mitchell Patent No. 1,971,115, issued August 21, 1934.

The invention is illustrated in a preferred embodiment in the accompanying drawings, in which- Figure 1 is a broken front elevational view of a multipleater machine equipped with the improved sewing mechanisms;

Figure 2 is a broken sectional View, taken as indicated at line 2 of Figure 1;

Figure 3 is a broken sectional view, taken as indicated at line 3 of Figure 1;

Figure 4 is a broken'sectional view, taken as indicated at line 4 of Figure 3;

Figure 5 is an enlarged fragmentary elevational view of the gearing shown in Figure 4;

Figure 6 is a broken sectional view, taken as indicated at line B of Figure 1;

Figure '7 is a broken top plan view of the mechanism shown in Figure 6;

Figure 8 is a broken sectional view, taken as indicated at line 8 of Figure 6;

Figure 9 is a broken plan sectional view, taken as indicated at line 9 of Figure 6;

Figure 10 is a broken plan view of the bed of the machine disposed beneath the sewing-head;

Figure 11 is a broken sectional view of the thread-guiding mechanism, taken as indicated at line H of Figure 12;

Figure 12 is a broken front elevational view of the thread-guiding device;

Figure 13 is a broken front elevational view, partly in section, of the sewing-head;

Figure 14 is a broken side elevational view,

partly in section of the same;

Figure 15 is a broken plan sectional view, taken as indicated at line I5 of Figure 13;

Figure 16 is a broken plan view, partly in section, taken as indicated at line l6 of Figure 13;

Figure 17 is an enlarged fragmentary front sectional view showing the sewing-needle at the beginning of its downward thrust;

Figure 18 is a fragmentary side elevational view showing the parts in the same position as in Figure 17;

Figure 19 is a view similar to Figure 17 but showing the needle at the end of its downward thrust;

Figure 20 is a fragmentary sectional view showing the parts in the same position as in Figure 19;

Figure 21 is a View similar to Figure 19 but showing the sewing-needle during its upward travel after hooking the sewing-thread;

Figure 22 is a fragmentary side elevational view in section, showing the parts in the position illustrated in Figure 21;

Figure 23 is a plan view of a completed seat cushion;

Figure 24 is a sectional view, taken as indicated at line 24 of Figure 23;

Figure 25 is a perspective view of a door panel having the upholstery sewed through the cardboard panel; and

Figure 26 is a broken sectional view, taken as indicated at line 26 of Figure 25 The sewing-mechanism disclosed herein is adapted for sewing panel boards or fabrics or other articles of considerable area. In sewing articles of this type, it will be apparent that sewing takes place at a point considerably removed from the edge of the fabric. Under these circumstances it is difiicult if not impossible to synchronize for proper co-action needles positioned at opposite sides of the fabric. Thisis for the reason that the synchronizing connection between needles at opposite sides of the fabric must extend around the edge of the fabric and therefore this synchronizing connection would necessarily have to be of considerable length. Any lost motion, backlash, imperfections in parts or wear would introduce errors of considerable extent.

According to the present invention, we provide two co-acting needles located on the same side of the fabric, carried by the same support and actuated from a single driving member. By this arrangement, it is possible to synchronize and coordinate these two needles with exceptional accuracy. According to the present invention these two co-acting needles cooperate with a loopforming device located beneath the fabric. The loop-forming device is operated in timed relation to the needles previously referred to, but, as will be evident, it is unnecessary that the looping device be timed with the same degree of accuracy as is necessary with the co-acting needles. The function of the loop-forming device is simply to form a loop which is picked up by the hooked sewing-needle and drawn through the fabric.

According to the present invention, and as will be described in detail subsequently, the two needles which are provided on the same side of the fabric are arranged to operate in the following manner: The hooked sewing-needle 43a moves downwardly and penetrates the fabric and picks up a loop of sewing-thread and draws the same upwardly through the fabric. As the hooked sewing-needle moves upwardly, the looper-needle 4fia moves forwardly directly beneath the sewing-needle, impaling a loop of sewing-thread. The looper-needle then moves transversely from beneath the path of the sewingneedle an amount sufficient to permit the sewingneedle to clear the looper-needle on its next downward descent. At the same time the looperneedle is positioned so that as the sewing needle descends it impales a loop formed in the looperthread carried by the looper-needle.

As will be readily evident, motion of the sewing-needle 43a and the looper-needle 46a must be controlled with great precision at high speed. Accordingly these parts are carried by a single sewing-head C and are interconnected by mechanism subsequently to be described for insuring their proper co-action.

In the embodiment illustrated A designates the main frame of a multipleater provided with a vertically movable cross-head A, a suction conveyor A and a forming roll A B, transmission mechanism for delivering power from the main drive shaft to the various parts of the sewingmechanism; C, sewing-heads which operate the sewing-needles and looper-needles; D, mechanism for swinging the sewing-heads C in timed relation to the travel of the material so as to avoid breakage of the sewing-needles; and E, thread-guiding mechanism for cooperating with the sewing-needles.

The multipleater construction is similar to that described in the Mitchell patent mentioned above, and the cross-head A, on which the sewingheads are mounted, is vertically adjustable on a pair of jack-screws 21. The material to be sewed is advanced from the rear of the machine by means of the usual suction conveyor A having a foraminous belt 28'. In making cushion fabrics, a lining fabric 29 is advanced in timed relation to cover fabrics 33 and cotton batts 3! under the forming roll A so as to be pressed into seam portions and intervening pleat fullnesses, as is well understood in the art.

As shown in Figures 1 and 2, power is delivered from the main power shaft 32 through the transmission B. As the cross-head A is adjustable, a jack-shaft 33 is journalled in a bracket 33 on the cross-head A and a positive driving connection is maintained with the shaft 32 by means of a floating gear 33 By means of suitable gearing, a jack-shaft 34, journalled in bracket 35 supplies power fora sprocket chain 35 which drives the shaft 35 which, in turn, supports and drives the sewing-heads C. An adjustable idler sprocket wheel 35 is provided to keep the sprocket chain 35 suitably tensioned. As best shown in Figures 1 and 3, the opposite end of the crosshead A is provided with ,a bracket 3'1 which has a sprocket wheel 3i and a driving gear 3l for operating the mechanism E and rotating a shaft 38 by means of a sprocket chain 31. An adjustable idler sprocket 31 is provided to keep the sprocket chain under suitable tension.

The construction of the sewing-heads C will be best understood by reference to Figures 6 to 9 and 13 to 16. Each of the heads is provided with a main frame 39 having a removable hood 39 which houses a double gear member 40 which is splined to the shaft 36 and is in mesh with a crank gear member 4| whose trunnions M are journalled in the frame 39. The member 4| provides a crank pin M which serves to drive a connecting rod 42 which is forked to provide a downwardly extending pair of arms 42. having their lower ends connected to a cross-head 2 which serves to reciprocate upwardly and downwardly a plunger member 43 equipped at its lower end with a hooked sewing-needle 43 The elbow portions of the connecting rod 42 are provided with slide blocks 42 to drive crank members which will be described below. The main frame affords suitable guide members 39 for the plunger 43 and suitable ways for the cross-head 42 are provided by guide strips 39 which are secured to the frame.

As shown in Figures 13, 14, and 16, a jackshaft 44 is journalled in the lower part of the frame, has a threaded shank portion 44 and is equipped with a fixed spur gear 44 which is held in mesh with a rack 43* provided on the plunger 43. .A pair of driving bell-crank members 45 are pivotally mounted on the shaft 44 and have their upwardly extending arms forked to make a slotand-block connection with the connecting rod 42 by means of the blocks 42. the cranks extend forwardly and carry a crossshaft 45 upon which is shiftably and pivotally mounted a looper bell-crank member 46. One of the rearwardly extending arms of the member 46 makes a threaded connection with the threaded shank portion 44 of the jack-shaft 44 so that when the jack-shaft is rotated through the ac tion of the rack 43* on the gear 44 the member 46 will be shifted laterally on the shafts 44 and 45 The other rearwardly extending arm of the member 44 is pivotally and shiftably supported on the jack-shaft. The downwardly extending portion of the looper bell-crank carries the looper-needle 46 The mechanism is enclosed by a shell 4! equipped with suitable lubricant holders 41 As best shown in Figures 6 to 9, a pair of presser feet 48 are normally urged down to compress the advancing material by means of compression springs 48 provided on plungers 48 The plungers are slidably mounted in a supporting bracket 49 which carries the driving shaft 36 and is fixed to the cross head A by means of suitable T-slots. A simple hand operated cam device 48 is provided at the top of the plungers 48 to raise the presser foot while the material is being placed in sewing position. As shown in Figure '7, this device has a pair of downwardly extending cam arms eccentrically journalled in glare ends of the plungers 48 by means of a pin As shown in Figures 6 and 8, the bracket member 49 is provided with a rigidly connected forwardly extending guide-bar 49 which extends between a pair of rearwardly extending guidearms 39 to reduce vibration and side sway of the sewing-heads C.

In order to avoid breakage of the sewingneedles, W n operating on heavy material such The lower arms of as cardboard, the mechanism D is provided to oscillate the sewing-heads C through a short are about the supporting and driving shaft 36. This mechanism is operated by the cross-shaft 38 which is provided with suitable eccentrics (i8 (see Figure 9) to drive a link 50 which is releasably connected to the sewing-head by means of the transversely shiftable lock-bolt journalled in the lower portion of the frame 39. The bolt 5| is provided with a handle 5| so that it may be shifted laterally against the spring latch 5| to permit the sewing-head to be drawn forwardly to facilitate threading the looper-needle 46. As will be readily understood, the shaft 38 is driven in timed relation to the shaft 36 and the eccentrics 38, which are splined to the shaft 38 are positioned so that the sewing-heads will be swung forwardly with the work while the sewing-needles are projected through the work and will be returned to their starting position while the needles 1 are retracted. This is for the purpose of moving the needles 43 in substantial unison with the motion of the fabric while the needles are engaged therein. For this reason, as is obviously necessary, the fabric is advanced at a predetermined rate relative to the rate of operation of the sewing machine, as disclosed in the Mitchell Patent 1,971,115, previously referred to.

The oscillating thread-guiding mechanism E is mounted in the bed of the machine beneath the path of the work. As shown in Figures 1, 3 to 5, and 11, an oscillating cross-shaft 52 is equipped at one end with a fixed gear 5'2 which is held in mesh with a spur gear 53 to which is secured a crank 54 adapted to be oscillated by the crank gear 3'1 through the medium of connecting rod 55. The gear mechanism and shafts are journalled in a suitable bracket 56 secured to the bed of the machine by means of suitable T-slots. At suitable intervals, transversely across the bed of the machine, are provided housing members 51 carrying the thread-guiding mechanism to cooperate with the sewing-needles. On each of the housings is journalled a rock shaft 58 provided with a fixed spiral gear 59 held in mesh with a cooperating gear 52 splined to the shaft 52. The front end of the oscillating shaft 58 is provided with a head provided at one edge portion with an upwardly extending horn-like member 59 and at the diametrically opposite edge with a pair of downwardly extending arms 59 which provide an open slot to receive a sewing-thread. The gearing is proportioned so that the shaft 58 oscillates through an arc of about 180 and the horn 59 is always in one of the upper quadrants. As will be further explained below, the oscillator acts to hook the sewing-thread in the sewing-needle alternately in each of the upper quadrants. To prepare the machine for operation a looperneedle thread 60 is led from a suitable source of supply above the sewing-heads, through a tensioning device, not shown, and is threaded through an eye provided in the looper-needle 46, as will be best understood by reference to Figures 6 and 17 to 22. As shown in Figure 6, the sewing-threads 6! are drawn through standard thread-tensioning devices 62 provided on the bed of the machine, through a thread-guide 63 depending from housing members 51 and between the guide-arms 59 to a position where the thread may be engaged by hooks provided in the sewingneedles. The fabrics to be sewed are advanced over ridge-forming bars 64 beneath the presser feet 48 to sewing position.

Operation The sewing-needle 43, looper-needle 46 and oscillating thread-guide operate in timed relation to form a semi-lock chain stitch as will be best understood by reference to Figures 17 to 22. In Figures 17 and 18, a loop of the sewing-thread BI is shown drawn up above the fabrics by the hooked sewing-needle 43 to a position where the loop is impaled by the rearward oscillation of i the looper-needle carrying the looper-thread 60. It may be noted that the looper-needle is directly below the point of the sewing-needle at this time. However, as the sewing-needle travels downwardly to again pierce the fabric, the looper-needle is moved slightly to the right, as viewed in Figure 19, to provide a slight amount of clearance and enable the sewing-needle to impale a loop forming in the looper-needle thread 60 in front of the looper-needle eye. During this same movement, the oscillator 58 is rotated counterclockwise, as viewed in Figures 19 and 20, and prepares a new sewing-thread loop in a position where its transverse portion will be caught by the upwardly open hook provided in the sewingneedle. As the sewing-needle starts upwardly, (see Figures 21 and 22) a new sewing-thread loop is picked off the oscillator and the oscillator is rotated back 90 so that the end of the thread may slip upwardly over the horn 59. The new loop is then drawn upwardly through the fabric to the starting position, shown in Figure 1'7, except that the sewing-thread 60 will now lie on the opposite side of the horn 59. During the next downward stroke of the sewing-needle all of the operations are repeated except that this time the oscillator rotates 90 clockwise instead of counterclockwise, as viewed in Figures 17 to 22. At the end of the second stroke the sewingneedle will be back in the identical position 11- lustrated in Figures 1'7 and 18. Thus, it will be understood that the horn 59 operates first in one of the upper quadrants and then in the other alternately, and two stitches are made during each arc of movement. The continued operation of the machine will result in the formation of a semi-lock stitch, as shown in Figure 18.

In making seat cushions of the type illustrated in Figures 23 and 24, the cover fabrics 39 are usually pre-cut and there is an interval between the sewing of the cushions. In using the present sewing-mechanism, the cover may be pulled out of the machine as rapidly as desired after it has cleared the sewing-needles and this will merely result in pulling out a length of the sewingthreads 6 I. As soon as the next cushion reaches sewing position, the needles are ready to commence sewing without having a re-threading operation. This feature is a distinct advantage in the saving of time and looper-needle thread.

If it is desired to sew the cover fabric and cotton batting directly to a cardboard backing panel 65, this can be done with the same sewingmechanism. In doing this the lining fabric 29 is not needed and the panels are advanced into sewing position in its place. The mechanism for operating the sewing-needles is very sturdy and has a powerful downward thrust which pierces the heavy panel Without difiiculty. The rocking movement of the sewing-head, in timed relation to the advance of the material, avoids breakage of the needles.

While we have illustrated and described several specific embodiments of our invention, it will be apparent to those skilled in the art that various additions, modifications, omissions, combinations and substitutions may be made which will be within the spirit and scope of my invention as defined by the appended claims.

What we claim as our invention is:

1. In a machine of the character set forth, a sewing-head comprising: a frame; an upwardly reciprocating rack gear in said frame provided at its lower end with a sewing-needle; a jackshaft journalled in the frame and provided with a fixed gear in engagement with said rack, said shaft being further provided with a threaded shank portion; a driving bell-crank pivotally mounted in said jack-shaft, means for driving one end of said crank in timed relation to the movement of the rack, the other end of the crank carrying a supporting shaft disposed in parallel relation to the jack-shaft; and a looper bellcrank pivotally and shiftably mounted on said supporting shaft, one arm of said looper-crank carrying a looper-needle and the other arm making threaded engagement with the threaded shank portion of the jack-shaft whereby the looper bell-crank will be shifted bodily in timed relation to the movement of the rack.

2'. A device as .specified in claim 1, in which the sewing-head is provided with a driving crank and connecting-rod for reciprocating the rack gear; the driving bell-crank making a slot-andblock driving connection with said connecting rod.

3. In a sewing machine, an axially reciprocable hooked sewing-needle for drawing loops of thread through a fabric, a looper-needle movable transversely of said sewing-needle, means for moving said looper-needle forwardly directly beneath said sewing-needle to impale the drawn loop While said sewing-needle is in upper position, and independent means for moving said looper-needle laterally out of the path of said sewing-needleas said sewing-needle descends.

4. In a sewing machine, an axially reciprocable hooked sewing-needle for drawing loops of thread through a fabric, a looper-needle movable transversely of said sewing-needle, means for moving said looper-needle forwardly directly beneath said sewing-needle to impale the drawn loop while said sewing-needle is in upper position, and independent means operable by movement of said sewing-needle for moving said looper-needle laterally out of the path of said sewing-needle as said sewing-needle descends.

5. In a sewing machine, a reciprocably mounted sewing-needle, a crank, a link connecting said crank and needle, a looper-needle, a shaft to which said looper-needle is pivoted, a threaded connection between said shaft and looper-needle, connections between said sewing-needle and shaft for rotating said shaft in accordance with reciprocation of said sewing-needle, whereby to effect transverse shifting of said looper-needle, and other means connecting said link to said looper-needle for oscillating said looper-needle about said shaft.

6. In means of the character set forth: a fabric-feeding means; thread-guiding means disposed beneath a seam and carrying a sewingthread; a hooked sewing-needle operatively mounted to work through the seam from the opposite side and draw a loop of the sewing-thread from said thread-guiding means through the same and through a looper-thread loop; a coacting looper-device operatively mounted to oscillate longitudinally of the seam beneath said needle to carry a looper-thread loop through the drawn sewing-thread loop and to move laterally out of the path of said sewing-needle sumciently to provide clearance for said needle, and means for driving said thread-guiding means, said sewing-needle, and said looper-device in timed relation as aforesaid.

'7. In means of the character set forth: fabricfeeding and forming means; thread-guiding means disposed beneath the fabric seams and carrying sewing-threads; sewing-heads provided with sewing-needles, each needle having a hooked operatively mounted to work downwardly through the seam into operative relation to said thread-guiding means and draw a loop of the sewing-thread upwardly through the seam and through a looper-thread loop; looper-needles on said heads mounted to oscillate to and from the sewing-needles and move laterally out of the path of the sewing needles to carry looper-thread loops through the the drawn sewing-thread loops, means for driving the sewing-needles and looper-needles in timed relation; and means for oscillating the sewing-heads in the direction of and in timed relation to the movement of said fabric-feeding means.

8. In a machine for manufacturing pleated upholstery: means for feeding fabrics and forming pleats and intervening seam-portions; means for feeding batts to the pleats; a plurality of sewing-mechanism equipped with vertically operating hooked sewing-needles and adjacent oscillating looper-devices with means for moving said looper-devices laterally while oscillating longitudinally of the seams beneath said sewingneedles; a plurality of thread-guiding devices disposed beneath the seams from which the sewing-needles hook the sewing-threads and draw loops thereof through the seams, said looperdevices being oscillatable to carry looper-thread loops through the sewing-thread loops after the latter have been drawn through the same, and means for driving said sewing-needle, and said looper-devices in timed relation as aforesaid.

9. A device as specified in claim 8, in which the sewing-mechanisms are carried by a crosshead provided with an upper transversely disposed drive-shaft upon which said sewing-mechanisms are pivotally mounted, and a lower eccentric shaft provided w-ith connecting means for swinging said sewing-mechanisms forwardly in timed relation to their sewing movement.

10. 'A device as specified in claim 8, in which the sewing-mechanisms are carried by a crosshead provided with an upper transversely disposed drive-shaft upon which said sewing-mechanisms are pivotally mounted, and a lower eccentric shaft provided with connecting means for swinging said sewing-mechanisms forwardly in timed relation to their sewing movement, said connecting means being detachably secured to the sewing-mechanisms by individual, shift'able bolts whereby the sewing-mechanisms may be detached below and swung forwardly about the upper shaft to facilitate threading the looperdevices.

11. A device as specified in claim 8, in which the sewing-mechanisms are mounted for lateral adjustment on a cross-head beneath which the fabrics pass, and the thread-guiding devices are mounted for lateral adjustment on the bed over which the fabrics pass.

12. A device asspecified in claim 8, in which the sewing-mechanisms are mounted for lateral adjustment on a cross-head beneath which the fabrics pass, and the thread-guiding devices are mounted for lateral adjustment on the bed over which the fabrics pass, and means is provided for driving the sewing-mechanisms and feedingdevices in timed relation.

13. In means of the character set forth: a fabric-feeding means; thread-guiding means disposed beneath a seam and carrying a sewingthread; a hooked sewing-needle operatively mounted to work through the seam from the opposite side and draw a loop of the sewing-thread from said thread-guiding means through the seam and through a looper-thread loop; a coacting looper-device operatively mounted to oscillate longitudinally of the seam beneath said needle to carry a looper-thread loop through the drawn sewing-thread loop and to move laterally out of the path of said sewing-needle sufiiciently to provide clearance for said needle and to position said looper-device relative to said sewingneedle so that said sewing-needle impales a looper-thread loop on said looper device.

14. In a sewing machine for straight-through sewing, thread guide means for supporting a sewing-thread at one side of a fabric, a head on the opposite side of said fabric, a hooked sewingneedle reciprocable on said head through said fabric to pick up a loop of sewing-thread from said thread guide means, a looper-needle mounted for oscillation on said head in accurately timed and spaced relation to said sewing-needle, and drive means for said needles.

15. In a sewing machine for straight-through sewing, thread guide means for supporting a sewing-thread at one side of a fabric, a head on the opposite side of said fabric, a hooked sewing-needle reciprocable on said head through said fabric to pick up a loop of sewing-thread from said thread guide means, a looper-needle mounted for oscillation on said head in accurately timed and spaced relation to said sewingneedle, and drive means for said needles, said drive means including a rotary member carried by said head, and connections intermediate said rotary member and both of said needles.

16. In a sewing machine, loop forming means at one side of a fabric for forming loops in a sewing-thread, a hooked needle on the opposite side of a fabric, means for reciprocating said needle through said fabric into position relative to said loop forming means to pick up a loop of sewing-thread therefrom and to draw said loop through to the opposite side of the fabric, an oscillating looper-needle supported adjacent said sewing-needle, said looper-needle having an eye for taking a looper thread, means for swinging said looper-needle forwardly beneath said sewing-needle to impale a drawn loop of sewing-thread and for moving said looperneedle laterally of its length to locate it in position such that said sewing-needle picks up a loop of the looper thread in back of the eye of said looper-needle on its next forward reciprocation.

17. In a sewing machine, a head, a needle carrying plunger mounted for reciprocation on said head, a shaft carried by said head and mounted for rotation about its axis, a second needle mounted on said shaft for oscillation thereabout, drive means for reciprocating said plunger and for oscillating said second needle, drive means intermediate said plunger and said shaft for rotating said shaft in accordance with reciprocation of said plunger, and connections intermediate said shaft and second needle for shifting said second needle axially of said shaft upon rotation of said shaft,

18. In sewing mechanism for forming a semilock chain stitch; a vertically reciprocating hooked sewing-needle operatively mounted to work through a seam and draw a loop of sewingthread through the seam and through a looperthread loop; a coacting generally horizontally oscillating looper-device operatively mounted above said seam to oscillate in timed relation to the movement of said sewing-needle and carry a looper-thread loop through the drawn sewingthread loop; a thread-guiding device mounted beneath the seam to oscillate in timed relation to the movement of said sewing-needle, said device having at one edge a pair of open ended thread-guiding arms to receive a thread and at the opposite edge a horn-like arm adapted to deflect the said sewing-thread downwardly to form a loop between the arms to be engaged by the hook in the sewing-needle and thereafter permit the thread to slip over the end of said horn, and means for driving said sewing-needle, said looper-device and said thread-guiding device in timed relation as aforesaid.

19. A device as specified in claim 18, in which the thread-guiding device is symmetrically designed and positioned with the horn extending upward in one position and oscillatable substantially to either side of said position so as to form a loop when the horn is turned to either side of said position.

20. A device as specified in claim 18, in which the thread-guiding device has its horn-like arm directed upwardly and is driven so as to oscillate said horn alternately substantially through the two upper quadrants and to form a thread-loop in each of the upper quadrants of movement alternately.

21. In a sewing machine, a hooked sewingneedle and a thread-guiding element, means for supporting said needle and element on opposite sides of a fabric to be sewed, means for reciprocating said needle axially through said fabric into operative relation with said element and return, and means operable in timed relation to said needle reciprocating means to oscillate said element about an axis transverse to the axis of said needle, said element comprising a slotted portion for the reception of a thread, and a horn, extending laterally from the axis about which said element oscillates to engage the thread and form a loop therein for engagement with said hooked needle.

22. In a sewing machine, a sewing-threadguiding element pivotally mounted about an axis, said element having thread-engaging portions on diametrically opposite sides of said axis, means for oscillating said element about said axis whereby said portions form a loop in said thread substantially across the axis thereof, and a hooked needle operable in timed relation to said element to engage said loop.

23. In a sewing machine, a hooked sewingneedle reciprocable vertically through a fabric, a thread-guide element beneath said fabric in operative relation to said needle, said element being oscillatable about a horizontal axis and having a thread-retaining portion and a looper horn, said horn normally extending upward from the thread-retaining portion, means for oscillating said element alternately in opposite directions from its upward position to form loops in the thread for engagement by said hooked needle.

24. In a sewing machine, a hooked sewingneedle reciprocable vertically through a fabric, a thread-guide element beneath said fabric in operative relation to said needle, said element being oscillatable about a horizontal axis and having a thread-retaining portion and a looper horn, said horn normally extending upward,

' upward position to form a loop on the opposite side of said horn.

25. In combination with a hooked sewingneedle, a thread-guide element for forming loops, in a position to be picked up by the hooked needle, said element. having an open ended slot through which thread may be introduced laterally, and a looper horn adapted to engage the thread intermediate said slot and a fabric being sewed, and means for oscillating said element to form loops.

26. In combination with a hooked sewingneedle, a thread-guide element for forming loops, in a position to be picked upby the hooked needle, said element having a thread-retaining portion through which sewing-thread may be drawn by said needle, and a looper portion adapted to engage said thread intermediate said retaining portion and a fabric being sewed, and means for oscillating said element such that said thread intermediate said thread-retaining portion and said looper portion is positioned to be engaged by said sewing-needle.

27. In a sewing machine, a hooked sewingneedle reciprocable vertically through a fabric, a thread-guide element beneath said fabric in operative relation to said needle, said element being oscillatable about a horizontal axis and having a thread-retaining portion and a looper horn, said horn normally extending upward from the thread-retaining portion, means for oscillating said element alternately in opposite directions from its upward position to form loops in thethread for engagement by said hooked needle, said horn being tapered so as to release said loop before said horn reaches upper position, so that on continued movement, said horn engages said thread on the other side of said horn.

28.. In means of the character set.- forth; a fabric-feeding; means; thread-guiding means disposed beneath a seam and carrying a. sewingthread; a hooked sewing-needle operatively mounted to work through the seam from the op posite side and drawa loop of the sewing-thread from said thread-guiding means through the seam and through a looper-thread. loop; a 00- acting looper device operatively mounted to us cillate longitudinally of the seam beneath said needle to carry a looper-thread loop through the drawn. sewing-thread loop and to move laterally out of the path of said sewing-needle sufficiently to provide clearance for said sewing-needle; said thread-guiding means comprising an oscillating member driven in timed relation to said sewingneedle so as to move the sewing-thread into a position to be engaged by the hook in saidsewing-needle; and means for driving said threadguiding means, said sewing-needle, and said looper device in timed relation as aforesaid.

29. In means of the character set forth: a fabric-feeding means; thread-guiding meansdisposed beneath a seam and carryinga sewing;- thread; a hooked sewing-needle operativelymounted to work through the seam from. the opposite side and draw a loop-of sewing-thread from said thread-guiding means through the seam and through a looper-thread. loop; a co- 7, acting looper device operatively mounted to es cillate longitudinally of. the seamv beneath said needle to carry a looper-thread loopthrough the drawn sewing-thread loop and to move laterally out of the path of said sewing-needle sufficiently 1 toprovide clearance for said sewing-needle; said thread-guiding means comprising an oscillating. member driven in timed relation to said sewingneedle so as to move the sewing-thread. into a position to be engaged by the hook. in saidsew-- ing-needle; said oscillatable member reverses its direction of oscillation during every alternate downward stroke of said needle; and means for 

